Re: [PATCH v2 02/17] psp: base PSP device support

[Jakub Kicinski <kuba@kernel.org>]

On Wed, 25 Jun 2025 19:55:01 -0400 Willem de Bruijn wrote:
> > +#define PSP_SPI_KEY_ID		GENMASK(30, 0)
> > +#define PSP_SPI_KEY_PHASE	BIT(31)
> > +
> > +#define PSPHDR_CRYPT_OFFSET	GENMASK(5, 0)
> > +
> > +#define PSPHDR_VERFL_SAMPLE	BIT(7)
> > +#define PSPHDR_VERFL_DROP	BIT(6)
> > +#define PSPHDR_VERFL_VERSION	GENMASK(5, 2)
> > +#define PSPHDR_VERFL_VIRT	BIT(1)
> > +#define PSPHDR_VERFL_ONE	BIT(0)  
> 
> Use bitfields in struct psphdr rather than manual bit twiddling?

Some call it manual bit twiddling, some call it the recommended kernel
coding style? ;)

> Or else just consider just calling it flags rather than verfl
> (which stands for version and flags?).

(Yes.)

> > +
> > +/**
> > + * struct psp_dev_config - PSP device configuration
> > + * @versions: PSP versions enabled on the device
> > + */
> > +struct psp_dev_config {
> > +	u32 versions;
> > +};
> > +
> > +/**
> > + * struct psp_dev - PSP device struct
> > + * @main_netdev: original netdevice of this PSP device  
> 
> This makes sense with a single physical device plus optional virtual
> (vlan, bonding, ..) devices.
> 
> It may also be possible for a single physical device (with single
> device key) to present multiple PFs and/or VFs. In that case, will
> there be multiple struct psp_dev, or will one PF be the "main".

AFAIU we have no ability to represent multi-PCIe function devices 
in the kernel model today. So realistically I think psp_dev per
function and then propagate the rotation events.